I just updated current yesterday and noted that the changelog has enabled xf86-input-synaptics - my understanding is that I do not have to patch the kernel now. I have configured the synaptics touchpad previously in linux and use the touch pad exclusively as a pointing device.
The xorg.conf below gives a moving mouse cursor but no tap-to-click

There are several ways to configure synaptics, and as jggimi, on systems that support syntaptics the X server now automatically loads the synaptics driver.

Without an xorg.conf, you can use synclient(1) or xinput(1) to set your preferences, if you still prefer xorg.conf you'll likely have to prevent the autoconfiguration of input devices. I believe there is a reference to this on the mailing lists or in the -current FAQ.